In PHP normally we use logical operators for validating. The operators performs operation with values and return Boolean value as TRUE or FALSE.
Normal logical operators are AND(&&) and OR(||). We can able to replace logical operators with logical strings.
Logical string and :
We can replace logical operator "&&" with "and". This string also working same as of Logical AND operation.
Logical string or :
We can replace logical operator "||" with "or". This string also working same as of Logical OR operation.